常规压缩下炭质板岩各向异性力学特征  

Anisotropic mechanical characteristics of carbonaceous slate under conventional compression

作　　者：胡涛涛 张哲昊 王栋 HU Tao-tao;ZHANG Zhe-hao;WANG Dong(School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China;School ofEnergy and Architectural Engineering,Shandong Huayu Institute of Technology,Dezhou 253034,Shandong,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]山东华宇工学院能源与建筑工程学院,山东德州253034

出　　处：《长安大学学报（自然科学版）》2024年第6期92-102,共11页Journal of Chang’an University(Natural Science Edition)

基　　金：国家自然科学基金项目(52378388)。

摘　　要：为探究层理倾角对炭质板岩力学特性的影响,开展不同层理倾角炭质板岩单轴和三轴压缩试验,研究层理倾角对炭质板岩强度、变形参数以及破坏形态的影响规律,并采用ABAQUS有限元软件建立内聚力模型进行数值模拟分析。研究结果表明:压缩过程中,不同层理倾角炭质板岩的应力随应变的演化过程呈压密、似弹性变形、破坏跌落3个阶段;三轴压缩下炭质板岩的应力-应变曲线几乎没有表现出压密阶段的特征,且随着围压增大,逐渐呈延性破坏特征;单轴压缩状态下,层理倾角为0°时炭质板岩表现出穿过层理面的剪切破坏,层理倾角为30°、45°时表现出沿层理面产生破坏面的弱面剪切破坏,层理倾角为90°时呈张拉-剪切破坏,不同层理倾角炭质板岩的破坏形态受层理倾角控制较强,受围压控制较弱;不同层理倾角炭质板岩的强度和变形参数均表现出各向异性特征,但各向异性程度不同,不同围压下炭质板岩峰值强度的各向异性比均在1.5以上,而弹性模量的各向异性比均在1.2~1.35;通过强度与围压的关系计算得出了炭质板岩的抗剪强度指标,其中黏聚力表现出明显各向异性。研究成果可为深埋炭质板岩隧道围岩失稳防控提供理论基础。To investigate the influence of bedding angle on the mechanical properties of carbonaceous slate,uniaxial and triaxial compression tests were conducted on carbonaceous slate samples with varying bedding angles.The objective was to study the effects of bedding angle on the strength,deformation parameters,and failure modes of the carbonaceous slate.Additionally,a cohesive zone model was established using ABAQUS finite element software for numerical simulation analysis.The research findings indicate that during compression,the stress-strain evolution of carbonaceous slate with different bedding angles exhibits three stages:compaction,quasi-elastic deformation,and failure with stress drop.Under triaxial compression,the stress-strain curves of carbonaceous slate rarely display compaction characteristics,and as confining pressure increases,the failure mode gradually transitions to ductile failure.In uniaxial compression,when the bedding angle is 0°,the carbonaceous slate exhibits shear failure across the bedding plane.At bedding angles of 30°and 45°,it shows weak plane shear failure along the bedding plane.When the bedding angle is 90°,tensile-shear failure occurs.The failure modes of carbonaceous slate with different bedding angles are strongly controlled by the bedding angle and less influenced by confining pressure.The strength and deformation parameters of carbonaceous slate with various bedding angles exhibit anisotropic characteristics,albeit to different degrees.The anisotropy ratios of peak strength for carbonaceous slate under different confining pressures are all above 1.5,while the anisotropy ratios of elastic modulus range from 1.2 to 1.35.The shear strength parameters of carbonaceous slate,derived from the relationship between strength and confining pressure,reveal significant anisotropy in cohesion.The research findings provide a theoretical foundation for the prevention and control of instability in surrounding rock of deeply buried carbonaceous slate tunnels.6 tabs,14 figs,21 refs.

关 键 词：隧道工程 炭质板岩 单三轴试验 各向异性 层理倾角 数值模拟 

分 类 号：U411[交通运输工程—道路与铁道工程]